Internal-combustion engine



Dec. 28, 1948.

J. B. FISHER INTERNAL-COMBUSTION ENGINE Filed March 15, 1946 2Sheets-Sheet `l` Dec. 28, 1948. J. B. FlsHER 2,457,652

INTERNAE- GOMBUSTION ENGINE Filed Maron 15, 1946 2 Sheets-Sheet 2.

JMeSJE/en Patented Dec. 28, 1948 Nr omen j VINTERNALv-colinzus'rronENGINE James B. Fisher, Waukesha, Waukesha Motor Company, corporation ofWisconsin Wis., assignor to Waukesha, Wis., a v

Application March 15, 1946, Serial No. 654,688

This invention relates to internal combustion engines, and has to dowith spark ignition injection engines.

My invention is concerned particularly with spark ignition injectionengines employing solid injection, in which the piston has an open topcupped upper end portion providing with the cylinder roof a combustionchamber, as the piston approaches the end of its compression stroke, andthe charging air enters the cylinder substantially tangentially thereofeffective for imparting to the air charge rotation about the cylinderaxis persisting substantially throughout the suction, compression andcombustion strokes of the piston. The fuel is injected into the rotatingair charge, at the proper point in the cycle, forming therewith thecombustible fuel-air mixture charge, which continues to rotate about thecylinder axis during the compression and combusion strokes of thepiston, as noted.

The known engines vabove referred to have proved to be highly efficientin general, but are not capable of satisfactory low speed idling and aresubject to frequent missing when idling or operating under light loadand at high speed. The rotation of the air charge, and with it theinjected fuel, causes stratification of the fuel-air mixture, so thatthe heavier particles of vfuel are at the radially outer portion of thecharge, which then is richer at such outer portion and becomesincreasingly leaner radially inward. When the engine is operating underlight load or idling, but very small or minute quantities of fuel areinjected. The fuel particles are thrown outward by centrifugal forceinto proximity to the surrounding wall of the piston cup, about whichthey travel in the rotation of the fuel-air mixture. Under suchconditions, there is no assurance that a mixture sufficiently rich infuel to be ignited by the spark plug will always bein sufciently closeproximity to the spark plug electrodes to assure ignition of the charge.For that reason, under the conditions stated,v objectionable missing ofthe engine occurs. While investigations made by me appear to confirm theabove explanation of the cause of missing when the engine is operatingunder the conditions stated, there may be other contributing factors notpresently apparent. However, whether the abovestated explanation iscorrect and complete or not, the fact is that objectionable missing ofthe engine occurs when idling and when operating at high speeds. Theknown engines referred to have been provided with means for cutting outoperation of some of the cylinders. with a view to lowering the idling 4Claims. (Cl. 12B-32) speed, but that involves increased expense andcomplication and is not altogether satisfactory.

My invention is directed to an engine of the type above referred tohaving simple and inexpensive means whereby the engine may be operatedat materially lower idling speeds than is possible with the knownengines, and objectionable missing of the engine when idling or whenoperating at high speed is eliminated or greatly reduced. I havediscovered that, bydeflecting part of the rotating fuel-air mixturecharge and thereby directing a portion thereof sufciently rich in fuelto be readily ignitible into the zone of the spark plug electrodes,assurance is had that the charge will be ignited and missing iseliminated. More specifically, I provide the piston cup with a defiectorso disposed that, as the piston approaches the end of its compressionstroke, part of the rotating fuel-air mixture charge is deiiected fromthe richer area thereof into the zone of the spark plug electrodes andis there subjected to locaized eddying or turbulence, assuring that fuelparticles are brought into sufliciently close proximity to the sparkplug electrodes to: be certainly ignited thereby. Preferably, I providetwo delectors defining, in eiect, a pocket opening radially outward fromthe combustion chamber within the piston cup and disposed substantiallyto receive the spark plug electrodes, when the piston is at the end ofits compression stroke, or substantially so. Further objects andadvantages of my invention will appear from the detail description.

In the drawings:

Figure 1 is an axial sectional view of the cylinder and cylinder headofa compression ignition injection engine embodying my invention,certain parts being shown in elevation and certain other parts beingbroken away and shown partly in section;

Figure 2 is a fragmentary underneath view of the cylindery head of theengine of Figure 1, taken substantiallyon line `fil-2 of the latterfigure lwith the upper end of the piston indicated in dot and dashlines- Figure 3 is a fragmentary pan view, on an enlarged scale, of thecylinder block and associated parts of the engine of VFigure 1, takensubstantially on line 3-3 of the latter figure, with the valves and thespark plug and the injection nozzle indicated in dot and dash lines;

Figure 4 is a sectional view, on an enlarged scale, of the piston, takensubstantially online 4 4 of Figure 3; and

Figure 5 is a sectional view, on an enlarged scale,

' anemona of the piston. taken substantially on line 8-8 of Figure 3*.

I have illustrated my inventiomby way of example, as embodied in anengine which is,/in general, of known construction and operation and abrief description of which, except as to those features having to doparticularly with my invention, will suffice. The engine E comprises acylinder block 8 in which is suitably mounted a cylinder barrel 1, witha cooling water space there about. receiving a piston 8 operatingtherein. The piston 8 is connected by a suitable connecting rod 8 and awrist pin III to the engine crank shaft (not shown), as/is known. Acylinder head I I is bolted on the upper end of cylinder block 8, withan intervening gasket I2. 'Ihe under face of cylinder head II is fiatand overlies the cylinder 1. being provided in the cylinder area withair inlet and burnt gas exhaust ports controlled by inlet and exhaustvalves I8 and I4, respectively, cylinder head II also having inlet andexhaust passages I8 and I8 leading to the inlet and exhaust ports.respectively. Each of the valves normally is held closedby a compressionspring I1 and is opened in propery timed relation to the operation ofthe engine by a rocker arm I8 actuated by a push rod I8 in a knownmanner. The cylinder head II is provided with a suitable cooling waterspace communicating with the water space of block 8, through suitableopenings in the latter and in head II, as is known.

The upper end portion of piston 8 is cup-shaped and open at its uper endproviding with the cylinder roof, when fpiston his in itsy inner orupper dead center position shown in Figure 1, a substantiallycylindrical combustion chamber 2U having a circumferential wail orcollar 2| extending upward from the body portion of piston 8 and abottom closure wall 22. When piston 871s in its position shown in Figure1 there is but slight clearance between it and the under face ofcylinder head II, approximately equal to the thickness of the gasket I2and only that required for mechanical reasons. The piston 8 is. ofcourse, provided with suitable sealing rings, as shown. The collar 2I ofpiston 8 is provided, at opposite sides thereof, with suitable recesses24 which accommodate the radially outer portions of the valves I8 and I4when piston 8 is in its inner dead center position. In that connection,it will be noted that the valves I8 and I4 are disposed adjacent thesides of the cylinder and overlie,`to a slight extent, at radially outerportions, the collar 2i of piston 8. That is desirable, particularlywith respect to the intake valve I3, as will be explained more fullypresently. If desired. the exhaust valve I4 may be disposed inward ofthe cylinder in non-overlying relation to collar 2I and, in such case,the recess 24 for the exhaust valve is not essential though Ipreferably'provide two recesses 24 disposed as stated. since the pistonsof certain cylinders of the engine may be disposed oppositely to theposition of the piston shown in the drawings. Collar 2l of piston 8 isfurther provided, substantially midway between the recesses 24, with anotch 28 providing clearance, when the piston is in its inner deadcenter position, for the inner end portion of an injection nozzle 28suitably mounted, in a known manner, in the cylinder head II. Thisnozzle 28 is connected to a fuel pump (not shown), by a tube 21, thepump supplying fuel to the nozzle in proper timed relation to theoperation of the engine, as is BMWA Thi? "injection nozzle 28 is ofknowntypo and is pro-A vided at its tip with two ports oropenings disposed toinject two diverging sprays of fuel into the combustion vchamber 20, asindicated at s in Figures 2 and 8.

As is shown, the air intake passage I8 is constricted at Ila, adjacentits inner end, and opens into the ,cylinder 1 substantially tangentiallythereof. The constriction Ila of intake passage I5 produces a Venturieffect so that, during the intake or suction stroke of piston 8,charging air enters the cylinder 1 substantially tangentially thereofand at high velocity. That imparts to the charge rotation yabout thecylinder axis. which rotation persists substantially throughout thesuction, compression and combustion' strokes of the piston 8. As thepiston 8 moves outward on its compression stroke, fuel is injected intothe rotating body of charging air by the nozzle 28 and is mixed with theair. Due to the continued rotation of the body of air and the fuel nowmixed therewith, the heavier particles of fuel are thrown outward bycentrifugal force and travel around the combustion chamber 28, at theinner g5 face of collar 2 I, the piston 8 being now approaching the endof its compression stroke. When the piston 8 is at or about the end ofits compression stroke, the fuel-air mixture charge is ignited by aspark plug 88 of known type suitably mounted in the cylinder head IIwith its electrodes 8I and 82 disposed in combustion chamber 20 adjacentcollar 2i thereof. In engines of thetype with which my invention isconcerned and of present day construction, frequent missing occurs whenidling and iwhen operating at high speed under 0 fiecting a light loads,due largely to stratification of the fuel-air charge caused by rotationthereof in the combustion chamber, as and for the reasons aboveexplained. I avoid that diillculty by deportion ofthe rotating fuel-airmixture charge into the zone of the electrodes 8| and 82 of the sparkplug 80.

As is shown more clearly in Figures 3 and 4, IV provide the upwardlyextending flange or collar 48 2i of the piston 8 with a defiectingelement or rib 84 extending generally lengthwise of piston 8 andprojecting radially inward of the combustion chamber 20. Rib 84 has asubstantially flat inner face 8l connected at one side to collar 2i by acurved element 38 merging smoothly into the inner face of collar 2|. Rib84 is also provided with a substantially flat side face 31 extendingfrom face 38, disposed substantially radially of combustion chamber 28and tapering downward in width, Spark plug 30 is so disposed that theelectrodes 8I- and 82 thereof are positioned adjacent face 81 of thedefiector element or rib 84, when piston 8 is at or near its inner deadcenter position shown in Figure 1. At that time, the fuel-air mixturecharge is rotating in the combustion chamber 20 in clockwise direction,as indicated by: the feathered arrows inV Figure 3. The. deector elementor rib 84 deflects a portion of the rotating charge radially inward ofthe combustion chamber 20. this deflected portion of the charge, as itpasses beyond rib 84, tending to move radially outward of the combustionchamber 20. due to centrifugal force.

Such outwardlmovement tends to reverse thev direction of flow of thedeflected portion of the charge so-that this portion is subjected to aneddying effect or localized turbulence in the zoneelectrodes of thespark plug, assurance is had 'that a readily ignitible fuel-air mixtureisL brought into proximity to the spark plug elec; trodes, with the fuelparticles of such mixture suiiiciently close to the electrodes to assureignition thereof by the spark plug. In that manner I assure that thefuel-air mixture charge will be ignited by the spark plug, particularlywhen the engine is idling or is operating at` high speed and under lightload. Also, by deectiiiga part of the fuel-air mixture charge.intothe-one of the spark plug electrodes in theqmaniienstated, theengine may be idled at much lowrsp'eed than is possible in the knownengines of this type not provided with such deilector means, above rferred to.

Preferably, I provide two deflector elements or ribs 34 spaced anappreciable distance apart circumferentially of collar 2|. 'I'hese tworibs 34 define between them an open top pocket opening freely into thecombustion chamber substantially radially thereof and decreasingdownward in radial extent. The spark plug is disposed so that theelectrodes thereof are adjacent and substantially in pocket 40, when thepiston 8 is at or near its top dead center position, and is adjacent therib or deflector 34 which is the fol lowing one of such ribs withreference to the direction of rotation of the fuel-air mixtureM chargein the combustion chamber, to assure local turbulence in the zone of thespark plug electrodes, as and for the reasons above stated. Theprovision of two deilector elements or ribs 34 is-.not essential, sinceone thereof is sumcient assuming that the position of the piston withrespect to the spark plug remains unchanged. In practice, however, thepositions ofl the air intake passages and the sparkpgs' of certaincylinders of the engine may 'be reversed relative to other cylindersthereof, asiisfjknown, in which case the corresponding pistons'wouldalso b e reversed. By providing two defiecto ,elements or ribs 34, thepiston 8 may be used in its position shown in Figure 3, with the intakeand exhaust passages l5 and I6, respectively, disposed as thereindicated, or it may be turned through an angle of 180 and used to equaladvantage with intake and exhause passages reversed relative to suchpassages indicated in Figure 3, the kpositions of the injection nozzleand the spark plug being,

of course, also reversed relative to their posi-4 tions indicated inFigure 3. Referring further Vto the recesses 24 and notch 25 in collar2|, such recesses and notch have no appreciable effect `upon therotation of the fuel-air mixture charge in the combustion chamber, donot constitute elements of my instant invention and may be provided ornot as conditions may require.

,Comparative tests have demonstated that an engine provided with thedeilector means of my invention, as above described, is highly efcientand is not subject to the objectionable missing which occurs in theknown engines, above referred to, of the saine general Vtype but withoutthe deflector means of the engine of my invention. Further, Vthe engineof my invention will operate at a lower B, M. E. P. without throttlingthe intake air, than the known engines of this general type and, also,hassubstantially lower idling speeds than the latter engines.

As above indicated, changes in details may be resorted to withoutdeparting from the eld and end of its compression stroke and thecharging Y air enters the cylinder substantially tangentially thereofeffective for imparting to the air charge rotation about the cylinderaxis persisting substantially throughout the suction, compression andcombustion strokes of the piston; said piston having at its upper end asubstantially continuous upwardly extending circumferential flange,

a deflector element extending generally lengthwise of said piston andprojecting from said flange substantiallyv radially inward of saidcombustion chamber, and a spark plug disposed to have its electrodesadjacent the leading side of said deilector element in respect to thedirection ofV rotation of the fuel-air charge when said pistonapproaches the end of its compression stroke, said deilector elementbeing eifectlve for deiiecting inward of the combustion chamber therotating fuel-air charge and thereby creating in conjunction with thecentrifugal force tending to move said fuel-air charge outward localizededdying of the fuel-air charge at the electrodes of the spark plug.

2. In a spark ignition injection engine in which the piston has an opentop cupped upper end portion providing with the cylinder roof a combus'-tion chamber as the piston approaches the end of its compression strokeand the charging air enters the cylinder substantially tangentialiythereof effective for imparting to the air charge rotation about thecylinder axis persisting substantially throughout the suction,compression and combustion strokes of the piston; said piston '.havingat its upper end a substantially continuous 'upwardly extendingcircumferential flange and a pocket open at its radially inner side tosaid combustion chamber and extending substantially radially outwardtherefrom and closed at its radially outer side by said flange, a.deector element at each end of said pocket extending generallylengthwise of said piston and projecting from said pocket substantiallyradially inward of said combustion chamber and connected to said flangeby a surface curved radially inward of said combustion chamber towardsaid deflector element and merging into Vsaid flange, and a spark plugdisposed to have its electrodes substantially lin said pocket when saidpiston approaches the end of its compression stroke.

3. A piston for use in a spark ignition indection engine in which thepiston has an open top cupped upper end providing with the cylinder roofa. combustion chamber as the piston approaches the end of itscompression stroke and the charging air enters the cylindersubstantially tangentially thereof effective for imparting to the aircharge rotation about the cylinder axis deector element beingsubstantially fiat and radial to said combustion chamber and theA otherside of said deiiector element being curved inward of said combustionchamber and merging into said flange.

4. A piston for use in a spark ignition injec- /ion engine in which thepiston has an open top /cupped upper end providing with the cylinderroof a combustion cham-ber as the piston approaches the end of itscompression stroke and the charging air enters the cylindersubstantially tangentially thereof effective for imparting to the aircharge rotation about the cylinder axis persisting substantiallythroughout the suction, compression and combustion strokes of thepiston; said piston having at its upper end a substantially continuousupwardly extending circumferential flange, and two deector elementsextending generally lengthwise of said piston projecting from said ange4substantiallyy radially 4inward of said combustion chamber and spacedapart circumferentially of said flange', the opposed' sides of saiddeector elements being substantially nat and radial to said combustion4chamber and the other sides thereof being respectively curved inward ofsaid combustion chamber and merging into said ange.

JAMES B. FISHER.

REFERENCES CITED The following references are of record in the `iile ofthis patent: y

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